/*******************************************************************************
 * Copyright 2017 Bstek
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License.  You may obtain a copy
 * of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations under
 * the License.
 ******************************************************************************/
package com.bstek.urule.console.servlet;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.bstek.urule.exception.RuleException;


/**
 * @author Jacky.gao
 * 2016年6月3日
 */
public abstract class BaseServletHandler implements ServletHandler {

    protected void invokeMethod(String methodName, HttpServletRequest req, HttpServletResponse resp) {
        Method method;
        try {
            method = this.getClass().getMethod(methodName, new Class<?>[]{HttpServletRequest.class, HttpServletResponse.class});
            method.invoke(this, new Object[]{req, resp});
        } catch (NoSuchMethodException | SecurityException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
            throw new RuleException(e);
        }
    }

    protected String retriveMethod(HttpServletRequest req) throws ServletException {
        String path = req.getContextPath() + URuleServlet.URL;
        String uri = req.getRequestURI();
        String targetUrl = uri.substring(path.length());
        int slashPos = targetUrl.indexOf("/", 1);
        if (slashPos > -1) {
            String methodName = targetUrl.substring(slashPos + 1).trim();
            return methodName.length() > 0 ? methodName : null;
        }
        return null;
    }
}
